Following one man's task of building a virtual world from the comfort of his pajamas. Discusses Procedural Terrain, Vegetation and Architecture generation. Also OpenCL, Voxels and Computer Graphics in general.

Only 7% of ProcWorld readers come from Germany. For the English readers I though it would be nice to post the original round of questions I got from Golem, along with the answers:What are you working on at the moment? What are you most proud of in that regard? Right now I am working on real-time architecture. Buildings are generated as you approach them. It is challenging for many reasons. First you need ways to teach the system how to generate interesting buildings. Then you need to make it happen really fast. It is the worst combination possible: a hard problem that needs to be solved in very little time.

I am proud of the potential. It is not obvious right now, but as the hardware continues to grow this platform could produce incredibly rich environments.

What does procedural generation mean for artists? How will it transform their job - and how will they have to adapt to benefit?

Robots are coming for our jobs everywhere, even journalism is being automated (you could be a robot for all that I know). The key question is how creative your job really is. If you perform unimaginative tasks, even as a "creator", odds are you will be replaced by some technology. Artists are no exception. How to adapt? Be more human, less robotic :)

What makes procedural generation important for the future? What will it enable?

It helps looking at the past first. I see three ages in procedural generation. The first coming was when storage and delivery was very limited, so there was an advantage in generating stuff on-the-fly. This is when games like Elite first appeared. We were very forgiving as an audience back then. You could throw a few points on screen and call it a galaxy.

Then hardware grew to a point where more realistic representations could be stored and rendered. At this point it became possible to pack quality artwork into a product. This gave us the second age, where most content was hand made. We are still in that era. Consumer grade hardware, like current console generation, is not able to produce content that is rich enough to challenge human-created content. There is some proceduralism there and there, but it is relegated to the background.

If Moore's law continues to hold, we will enter a third stage. Hardware is growing at a faster pace than artist output. The industry needs to keep moving the new hardware, but it is becoming prohibitively expensive to do it in the traditional model. Automation is the only choice.

What will be the future? You can think of a variation of the Turing's test: A human plays a game without ever realizing most of it was created by a computer.

In what way could it make gaming better? Or worse? ;-)

I think it will produce a lot of horrible games. Look at what the auto-tune has done for music. But then it will produce some unique experiences.

I also think we should not worry about that. Imagine a house is burning and the people inside are wondering whether it is sunny outside. It does not matter because they have to come out anyway. Automation is inevitable in the games industry, otherwise the whole industry will stagnate and burn like the house. Whether it will be worse or better, makes no difference.

What are the worst problems - from a programming and an artistic standpoint?

Let's say you were building a game the traditional way. You would have one guy doing the story, some guys do concept art, some other guys do the actual environments, level design, others will create and place props and so on. In theory all of these tasks can be automated.

The reality is some of these tasks are a lot simpler. For instance the guy modeling rocks can be easily replaced, but what about the one doing the concept art or the storyline?

There are some tough problems there. They are on the fringe of AI and we have no solutions for them today. But then once you look at what we can do with automated translation, self-driving cars, and so on, we may not be far from that. There is also the advent of "the cloud" as a computing device. I think that changes everything.

What do you think has been the most important progress to procedural generation during the last years? An what can we expect from the future? And how important are hardware and 3D engines for the further advance of procedural content?

The hardware has evolved to a point where some cool things are now possible. We have known about them for many years. It was just too slow to try them.

There has been a lot of research in synthetic reality, for a long time now. The real bottleneck has been and continues to be the hardware. Look at the movie Avatar for example. It is a procedural world what you have there, still it costed millions to generate. This has to come to the point where an equally rich world could be generated by your home console or computer, or by cloud services you can afford.

Monday, December 3, 2012

The first one shows a bit of the architecture, also how a couple of useful underground passages can save you time while travelling:

The second is a trip I did to get close to a tower I saw. It seemed simple at the beginning, but the terrain had some severe accidents so I had to figure out my way. I found some caves that helped me get there, also saw I needed to do a quick bridge over a chasm. It runs at double the speed so you would not get bored by all the wandering. Also note that at the end of the video I carve some holes into the tower walls.

The next video also runs at double the speed. It shares the same beginning as the first video posted here, but goes a lot farther.

And the last video shows how the caves can sometimes go really deep underground. You often see cave openings into the surface, but also they could be right under your feet and you would not know. I cheated in this video by showing the wireframe, otherwise it would have taken an awful lot of time to find these caves.

Boy this was a tough one. I always knew it was coming, tried to postpone it for as long as I could.

In the past I had succeeded creating complex buildings out of L-Systems. While it was fast, it was for a different approach to world generation. It was for static game worlds like Skyrim's. I had the luxury of time.

In a world that generates as the viewer moves, most of the time I had for generation was already taken by the terrain and trees.

Architecture is something you cannot just instance. You want buildings to be different, even if they belong to the same class. I needed the actual grammar programs to run in real time, its polygonal output voxelized and then merged with the rest of the voxel data.

You may think going from polygons to voxels then back to polygons is an awful waste of time. It had been, except for the fact I needed changes made Minecraft-style to also work over buildings. When you are wielding that pickaxe you don't really care if that rock in front is a natural formation or a cathedral wall.

At the end I did manage to make it work. As usual most of the solution went into creating indices to accelerate the actual work.

I had to make compromises. For starters, the voxel resolution in the realtime engine is much coarser than what I had for the pre-computed worlds. This meant a lot of the detail in buildings had to go. This also applied to the following levels of detail. Detail had to be removed in all levels.

I also saw I needed simpler grammars just so the system could keep up in lower-end hardware. I found it common to have thousands of different buildings in a single scene. The solution I found was to pass the LOD parameter to the building grammar at evaluation time. It made it possible, but now the building programmer has to worry about creating different views for the same building.

I am still very happy with the results of something I feared almost impossible. There is room for improvement, and this is a good thing. The hard part is over.

I leave you with some screenshots of a single tower grammar that appears scattered everywhere. Please do not mind the lack of actual cities, or the fact it is the same tower over and over again. This is rather a test for the system. I will be posting some videos later.